Both the morphological and optical data varied considerably
in the present study. As shown in Figs. 9 and 10 such
variation seems to originate in part from the different sizes
of the eyes themselves. In addition, multiple measurement
errors might be superimposed on such inter-individual variations.
Any morphometric values might be incorrectly
measured if, for example, the section plane did not precisely
contain the median plane of the eye, or if the median
plane of the corneal lens were not precisely kept horizontal
on the microscopic stage in wholemount observation. Furthermore,
there was some doubt that the posterior margin
of the corneal lens might be distorted by the staining conditions
adopted. Inaccuracies might also be included in the
optical measurements. Images of 5 mm grids were reduced
to about 10 lm through the corneal lens (Fig. 2), and at
these dimensions it was not easy to measure the size of
the image precisely to two decimal places. In making direct
observations of a beam path, the convergence point of the
beam was diffused over a distance of more than 10 lm.
Despite the ambiguity in the data we obtained, however,
we discuss those data from a standpoint that their average
values do not lie far from the correct values for an eye of
average size.